Attendees say the summit will focus on the plight of the world’s poorest, which they argue went largely ignored at official United Nations-sponsored climate talks in Copenhagen last December.

The Copenhagen meeting was widely drubbed for failing to produce a new treaty to limit greenhouse gas emissions and critics said the deal it produced will not avert a climate catastrophe.

The “People’s World Conference on Climate Change and Mother Earth Rights,” which runs through Thursday, will draft new proposals to be offered for consideration at the next UN climate talks in Mexico at the end of the year.

Bolivia’s UN ambassador Pablo Solon said the conference, which was expected to draw some 18,000 people, was “the only way to get the climate change talks back on track.”

Nearly 130 countries, including many of the world’s poorest, will be represented at the Cochabamba conference.

Anti-globalization activists Naomi Klein of Canada and Jose Bove of France are set to attend, and organizers have also invited James Cameron, director of the blockbuster film “Avatar,” and James Hansen, a US researcher who was among the first to warn about climate change.

Indigenous leaders, including Nilo Cayuqueo, an indigenous Mapuche from Argentina, were also in town, concerned about the impact of climate change on their homelands.

“We have great extremes of heat and cold, and as a result we’re seeing illnesses and outbreaks that once had disappeared,” said Cayuqueo.

This week’s gathering will also give a giant megaphone to a left-leaning bloc of Latin American leaders, including presidents Rafael Correa of Ecuador, Fernando Lugo of Paraguay, Daniel Ortega of Nicaragua, Hugo Chavez of Venezuela and Evo Morales, the indigenous president of host nation Bolivia.

The conference will seek to refine proposals presented by Morales in Copenhagen that included the creation of a world tribunal for climate issues and a global referendum on environmental choices.

The conference begins the day after representatives from the world’s leading economies gathered in Washington for a preparatory meeting ahead of the December UN summit in Cancun.

The US-led Major Economies Forum comprises 17 countries responsible for the bulk of global emissions and excludes smaller nations such as Sudan whose firebrand negotiators held up sessions at December’s Copenhagen summit.

Washington hopes the closed-door talks will allow key nations to quietly assess what they can achieve heading into the next major climate summit in December in Cancun.

“Clearly, there is still a gap between the views of the developing and developed world,” State Department spokesman Philip Crowley said. “We’re going to see if we can, through the course of this discussion, narrow that down.”